The present invention relates to a conductive film, a display device equipped with the conductive film, and a method for determining a pattern of the conductive film.
Examples of a conductive film installed on a display unit of a display device (hereinafter also referred to as “display”) include a conductive film for electromagnetic shields and a conductive film for touch panels (for example, see JP 2009-117683 A and JP 2011-216379 A).
JP 2009-117683 A, a published patent application filed by the same applicant as the present application, discloses that a second pattern, which is generated from second pattern data in which the relative distance between spectrum peaks of two-dimensional Fourier spectrums (2DFFT Sp) of the respective pattern data of a first pattern such as a pixel array pattern (for example, a black matrix (hereinafter also referred to as “BM”) pattern) of a display and the second pattern such as an electromagnetic shield pattern is greater than a predetermined spatial frequency, for example, 8 cm−1, is automatically selected.
JP 2009-117683 A also discloses that when the relative distance is not greater than the predetermined spatial frequency, changing of one or more of a rotation angle, a pitch and a pattern width in the second pattern data to generate new second pattern data is repeated until the relative distance is greater than the predetermined spatial frequency.
In this way, in JP 2009-117683 A, it is possible to automatically select an electromagnetic shield pattern that can suppress the occurrence of moire and that can avoid an increase in surface resistivity or degradation in transparency.
JP 2011-216379 A, another published patent application filed by the same applicant as the present application, discloses a transparent conductive film having a mesh pattern comprising a plurality of polygonal meshes, in which the mesh pattern is formed such that, in relation to a centroid spectrum of respective meshes, an average intensity on the side of a spatial frequency band higher than a predetermined spatial frequency, for example, a spatial frequency at which a human visual response characteristic corresponds to 5% of the maximum response, is greater than an average intensity on the side of a spatial frequency band lower than the predetermined spatial frequency.
It is stated in JP 2011-216379 A that a transparent conductive film is provided which is capable of lowering the sensation of granular noise caused by the pattern and significantly enhancing the visibility of objects to be observed, and has a stable power capability even after being cut.